Traditional TFT LCD displays are manufactured by forming thin-film semiconconductor transistors on the surfaces of glass substrates. The prevailing thickess of the glass substrates used is about 500-700 μm. Significant capital investment has been made by LCD panel makers on the production lines for these relatively thick glass substrates.
There is a growing trend that the glass substrates underlying the TFT devices are becoming thinner and lighter. Glass substrates having a thickness lower than 500 μm, such as 300 μm, 100 μm or even thinner, can be desirable for certain display applications, especially for portable devices such as laptop computers, hand-held devices and the like. One way to achieve such low thickness in the device is to first fabricate a device based on a thicker glass substrate, followed by chemical and/or mechanical thinning of the substrate. While this process is effective, it would be desirable to fabricate the device directly on a thin substrate, thus eliminating the step of thinning
However, handling of such thin glass substrates presents a significant technical challenge for the panel makers because many of the production lines were not designed to have the capability to process such significantly thinner glass substrates without significant process modification.
One proposed modification to the conventional process for thick glass substrates is to bond the thin glass substrates to a carrier glass substrate by using a bonding agent such as an adhesive compatible with the down-stream process steps. The larger combined thickness of the bonded substrates can solve the handling issues on conventional TFT fabrication lines.
Upon formation of the semiconductor devices on the surface of thin, functional glass substrate supported by the carrier substrate, the functional substrate needs to be released from the carrier susbstrate. However, it is not a trivial matter to effect the debonding without causing damage to the functional substrate and/or devices formed thereon.
Thus, there is a need of an effective method for debonding a thin functional substrate from a carrier substrate.
The present invention satisfies this and other needs.